Plague discovered in Palomar Mountain fleas

Health officials warned residents Wednesday to protectthemselves from two potentially deadly diseases carried by insects-- plague in Palomar Mountain fleas and the mosquito-borne WestNile virus making its way toward San Diego County.

The disease-carrying bugs could make pets and people sick,health officials said.

On Palomar Mountain, a handful of squirrels have been infectedwith plague, the same flea-borne disease that killed millions inEurope in the Middle Ages, the San Diego County Department ofEnvironmental Health announced Wednesday.

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Also on Wednesday, authorities discovered West Nile virus, asometimes fatal disease carried by mosquitoes, in some ImperialValley insects. The discovery of the virus, which causes fever,achiness and meningitis, signals West Nile’s entrance intoCalifornia -- and likely into North County.

The infected mosquitoes were found at the Salton Sea, about 80miles northeast of San Diego. Chicken flocks in nearby Niland alsotested positive for the disease, according to preliminaryresults.

“It’s not a matter of if West Nile will come to us. It’s amatter of when,” said Chris Wickham, environmental healthdepartment supervisor.

A traveler visiting the San Diego area was hospitalized forsymptoms of the virus, the health department said this week.Department officials said the man had traveled cross country by carand likely picked up the virus from mosquitoes in New Mexico.

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Plague at Palomar

On Palomar Mountain, health officials have found three squirrelsinfected with plague, they said Wednesday.

No reported human cases of plague have ever been contracted inthe county, health officials said, and it’s not unusual to discoverplague in a few squirrels on the mountain each year. But countyhealth officials say there is a slight chance infected fleas in twoof the mountain’s campgrounds could infect campers, hikers and petsin the area.

Squirrels at the Observatory Campground and nearby Fry Creekcampground were found infected with the plague, the departmentsaid. Plague causes fever, chills, swollen lymph nodes -- bubonicplague -- and in severe cases, lung infections such as pneumonia,known as pneumonic plague.

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“I wouldn’t sleep on the ground out there,” Wickham said ofPalomar Mountain, where fleas near the soil transmit the disease toground squirrels and other mammals.

“These squirrels were hot with plague,” he said. “If you rollout your sleeping bag next to a burrow of ground squirrels and thefleas decide the squirrels aren’t tasty enough and come munch onyou, you could conceivably be putting yourself in danger.”

The infected fleas like altitudes of 3,000 feet or more and havenot been found on ground squirrels in other areas, he said.

But infected fleas could latch onto pets and be carried intohomes and cities, said Dr. Michele Ginsberg of the county healthdepartment.

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“Fleas can easily hitchhike home and bite people who were neveron the mountain in the first place,” Ginsberg said.

The department dusted parts of the two campgrounds withflea-killer Wednesday. The campgrounds remain open, a park rangerthere said by telephone. Signs will be posted warning visitors tostay away from squirrels and other wild animals. Campgroundvisitors should see a doctor if they experience fever, chills orswollen lymph nodes within two to six days of being on themountain, Ginsberg said.

West Nile also coming, officials say

As they dusted for plague-infected fleas, health officials alsowarned that West Nile is on its way.

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“We don’t have a health emergency right now, but we’re expectingone,” said Wickham of West Nile.

The virus has infected about 600 people in at least 28 states,including Colorado, Texas and New Mexico. A large percentage ofpeople infected by mosquitoes show few or no symptoms, but elderlypeople, children and people with immune system problems are mostvulnerable to the virus, according to the Centers for DiseaseControl and Prevention in Atlanta.

The best way to protect against the virus and othermosquito-borne diseases is to protect yourself from skeeters in thefirst place, said the department. Residents should use flea andtick repellent containing the chemical DEET and cover up withsleeves and pants. Residents should also empty all vesselscontaining stagnant water, including buckets, baby pools and anywet place where mosquitoes could breed.

Lagoons, fish ponds and swimming pools that are not properlymaintained also can become “mosquito factories,” Wickham said. Thedepartment has released mosquito-killing chemicals in the San Elijoand Buena Vista lagoons this summer to keep mosquitoes at bay.

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The department also gives out free mosquito-eating fish forresidential ponds.

For more information on West Nile virus or mosquito-eating fish,go to www.sdfightthebite.com or call (858) 694-2888. For moreinformation about plague, go to www.cdc.gov.